Phytophthora root rot yield loss tool

Phytophthora root rot (PRR) disease can cause significant yield losses in chickpea in northern NSW and southern areas of Queensland. Losses are estimated to cost $8.2 million per year in wetter than normal seasons or following periods of high soil saturation. Chickpea grown on vertosol soils have the largest issue with PRR.

NSW DPI has developed a handy decision-making tool (in an excel spreadsheet) for chickpea producers and their advisors to estimate yield and associated income losses due to PRR in the crop. The estimated potential yield and economic losses can then be compared to the cost of growing the crop out to maturity (input costs) to determine whether the crop is viable to take through to harvest or if it should be terminated.

Once a crop is infected with PRR there are currently no effective in-crop management options such as there are for ascochyta blight (AB) control. Chickpeas can be expensive to grow, especially in wet years where multiple fungicide applications are needed to manage diseases such as AB. These wet years will also favour PRR development. This tool can assist with critical in-season decision-making in years when severe yield losses are expected and an economic decision is required to continue managing or abandoning the crop.

The tool can also be used for several target yields, typical of various rainfall zones or an anticipated rainfall within a region. Growers and advisors can enter variables such as input costs, expected grain yield of non-PRR affected areas and expected grain price into the tool for two soil types (grey or black vertosol) to determine:

  • input costs to harvest
  • estimated profit loss: from crop yield losses and input costs from the time of PRR detection.

There are separate assessment sheets for either black or grey vertosols.

Download the tool here

This work was supported by a co-investment between NSW DPI and the Grains Research and Development Corporation (GRDC) as part of the GAPP Initiative. The GAPP is a long-term partnership between NSW DPI and the GRDC, focused on building research capacity in projects of importance to northern region growers.

For more information contact
Sean Bithell
Research Officer (Pulse Pathology)
NSW Department of Primary Industries
4 Marsden Park Rd
Tamworth NSW 2340
M: 0429 201 863
E:  sean.bithell@dpi.nsw.gov.au